Pulling device for woolen yarn drafting arrangements



Oct. 4, 1966 HANS RUDOLF GRUNDER 3,276,196

PU LLING DEVICE FOR WOOLEN YARN DRAFTING ARRANGEMENTS Filed Feb. 12. 1965 IN VEN TOR Hfl zvs- Rum LF. GRUNDER TTORA/EX.

United States Patent 3,276,196 PULLIN G DEVICE FOR WOOLEN YARN DRAFTING ARRANGEMENTS Hans-Rudolf Grunder, Winterberg, Switzerland, assignor to Rieter Machine Works Ltd., Winterthur, Switzerland, a corporation of Switzerland Filed Feb. 12, 1965, Ser. No. 432,119 Claims priority, application Switzerland, Feb. 25, 1964, 2,322/ 64 12 Claims. (CI. 57-51) The present invention relates to a pulling device for Woolen yarn drafting arrangements including a false twist element in the drafting field, as shown in the patent application Ser. No. 354,676 of March 25, 1964 of E.

F. Hoyler.

In the pulling device disclosed in the aforesaid patent application and provided in a drafting arrangement including two pairs of rolls for drafting roving the straight line connecting the nips of the pairs of rolls which define the drafting field, is intersected by a stationary oblong transverse yarn guide which is placed normal to said straight line. A second oblong transverse yarn guide intersects the aforesaid straight line adjacent to said stationary yarn guide, is placed normal to said straight line, and rotates around an axis substantially coinciding with said straight line and extending through the middle of the yarn guides so that the spinning material traveling from one pair of rolls to the second pair of rolls is deflected, i.e. pulled, at each revolution of the rotating yarn guide.

The aforedescribed yarn guides which are preferably in the form of smooth, cylindrical rods have the disadvantage that the extent of the yarn deflection is not definitely controlled and that there is no possibility of effecting additional pullings at each revolution of the second yarn guide.

It is an object of the present invention to provide pulling means which avoid the aforesaid disadvantages of the aforedescribed pulling means by providing guides in the form of rods whose surface is curved several times longitudinally of the rods. This may be accomplished by undulating the rods or by undulating only the surface of the rods. In a modification the rod may be provided with annular bulges or recesses whereby the bulges as well as the recesses diminish from the center of rotation to the outside.

An additional feature of the yarn guide according to the invention resides in the provision of the zone containing the axis of rotation of the guide between two neighboring zones wherein the active diameter of the guide is relatively great, This limits the amplitudes of the yarn deflection. By permitting the yarn to jump from one recess into another the pulling frequency can be increased.

The novel features which are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, and additional objects and advantages thereof will best be understood from the following description of embodiments thereof when read in connection with the accompanying drawing, wherein FIG. 1 is a schematic longitudinal sectional view of a drafting arrangement including a false twist device provided with pulling means according to the invention.

FIG. 2 is a side view of a portion of a yarn guide forming part of the pulling means shown in FIG. 1.

FIG. 3 is a side view of a portion of a modified yarn guide.

FIG. 4 is a side View of a portion of a further modification of a yarn guide which may be used in the pulling device shown in FIG. 1.

FIG. 5 is a side view of a portion of yet another modi- 3,276,196 Patented Oct. 4, 1966 Ice fication of a yarn guide according to the invention.

FIG. 6 is a side view of a portion of a further modification of a yarn guide according to the invention.

FIG. 7 is a side view of a portion of a further variation of a yarn guide according to the invention.

FIG. 8 is a cross sectional view of the yarn guide shown in FIG. 7.

FIG. 9 shows a portion of another variation of a yarn guide according to the invention.

FIG. 10 shows a cross section of the yarn guide illustrated in FIG. 9.

Referring more particularly to FIGURE 1 of the drawing numerals 1 and 2 designate roller pairs confining a drafting field. A stationary bushing 4 mounted on frame 3 rotatably supports a funnel element 5 on the lower end of which needles 9 forming a funnel are mounted which impart a false twist to a spinning material 6. The spinning material leaving the delivery rollers 2 moves onto a cop, not shown. A transverse rod 7 is mounted to the lower end of the bushing 4 which rod is placed substantially diametrioal with respect to the bushing and normal to the path of the yarn 6. The lower end 8 of the needle funnel element 5 supports a transverse rod 10 diametrical of the element 5 to rotate therewith around a rotation axis extending through the center of the rod 10. The distance between the stationary rod 7 and the rotating rod 10 in the direction of the path of the yarn is such that the spinning material can easily pass between the rods, also when the rods are in parallel position with respect to one another.

Pulling the yarn is effected as follows: The yarn may be on the left side of the stationary rod, as shown in FIGURE 1. The rotating rod 10 pushes the yarn along the side of the rod 7 until the friction between the yarn and the rods becomes so great that sliding of the yarn along the rods is prevented. The yarn then passes between the rods 7 and 10 along an S-shaped path and snaps back into the initial position when the rod 10 has completed a full turn. The element 5, 8, 10 which is rotated by a cord drive, not shown, makes about 2000 to 3000 revolutions per minute so that the yarn is subjected to 2000 to 3000 pulls per minute while passing through the drafting arrangement,

In the embodiment of the invention shown in FIGURE 2 the rotating rod 10 has an undulated surface 11, the rotation axis 12 of the rod coinciding with a reduced diameter portion of the rod.

FIGURE 3 shows a rod having axially spaced annular projections 13 whose outer diameter decreases with increasing distance from the rotation axis 12.

In the modification shown in FIGURE 4 the rotating rod 14 is provided with annular recesses or grooves 15 whose bottom diameter increases with increasing distance of the grooves from the rotation axis 12 of the rod i.e. from the center of the rod.

FIGURE 5 shows a rod having annular recesses or grooves 16 placed closely to one another and whose bottom diameter decreases with increasing distance from the rotation axis. With this structure the deflection of the yarn is reduced without reduction of the pulling frequency.

FIGURE 6 shows an undulated rod 17, a wave trough 18 coinciding with the rotation axis 12.

FIGURES 7 to 10 show a rod having protuberances 19 with recesses therebetween in a plane which is normal to the rotation axis 12 of the rod. The rod proper which carries the protuberances may have a circular cross section as shown in FIGURE 8 or may have a rectangular cross section as shown in FIGURE 10.

In lieu of the stationary rod 7 a slot 20 as shown in FIGURE 11 may be placed diametrically of the bushing 4 for guiding the spinning material. The edges 21 3 of the element forming the slot may be curved, for example undulated.

What is claimed is:

1. A pulling device for periodically pulling woolen yarn passing through a drafting arrangement, comprising:

a stationary yarn guide placed in the drafting arrangement transversely to the direction of movement of the yarn and engaging with the yarn, and

a rotating yarn guide constituted by a rodlike element placed in the drafting arrangement normal to the direction of movement of the yarn and rotatable around an axis extending through the center of said element and substantially coinciding with the path of the yarn, said yarn guides being placed at a small distance from one another for affording passage of the yarn between said guides,

said rodlike element having a surface curved several times in opposite directions and longitudinally of said rodlike element.

2. A pulling device as defined in claim 1 wherein said rodlike element is undulated.

3. A pulling device according to claim 2 wherein the rotation axis of said rodlike element extends through a wave trough formed by the undulated element.

4. A pulling device as defined in claim 1 wherein said rodlike element has an undulated surface.

5. A pulling device as defined in claim 1 wherein said rodlike element has a plurality of annular projections coaxial with and spaced longitudinally of said rodlike element.

6. A pulling device according to claim 5 wherein the outer diameter of said projection decreases with increasing distance of the projections from the rotation axis of said element.

7. A pulling device as defined in claim 1 wherein said rodlike element has a plurality of annular recesses coaxial with and spaced longitudinally of said element.

8. A pulling device according to claim 7, wherein the depth of said recesses is greatest at the center of said element and decreases with increasing distance of the recesses from the rotation axis of the element.

9. A pulling device according to claim 7 wherein the depth of said recesses is smallest at the center of said element and increases with increasing distance of the recesses from the rotation axis of the element.

10. A pulling device as defined in claim 1 wherein said rodlike element is provided with a plurality of recesses in a plane normal to the path of the yarn.

5 11. A pulling device for periodically pulling woolen yarn passing through a drafting arrangement, comprismg:

a stationary yarn guide placed in the drafting arrangement transversely to the direction of movement of the yarn and engaging with the yarn, and

a rotating yarn guide constituted by a rodlike element placed in the drafting arrangement substantially normal to the direction of movement of the yarn and rotatable around an axis extending through the center of said element and substantially coinciding with the path of the yarn, said yarn guides being placed at a small distance from one another for affording passage of the yarn between said guides,

said rodlike element having portions of relatively great diameter alternating with portions of relatively small diameter longitudinally of the element for forming an undulatory surface of said element, said rotation axis extending between portions of said element having relatively great diameters.

12. A pulling device for periodically pulling woolen yarn passing through a drafting arrangement comprising:

a stationary yarn guide member placed in the drafting arrangement and having a slot placed transversely to the direction of movement of the yarn, the yarn passing through said slot, and

a rotating yarn guide in the form of a rodlike element placed in the drafting arrangement substantially normal to the direction of movement of the yarn and rotatable around an axis extending through the center of said element and substantially coinciding with the path of the yarn, said member and said rotating yarn guide being placed at a small distance from one another for afiording passage of the yarn between said member and said rodlike element when said rodlike elernent is parallel with said slot,

said rodlike element having a surface curved several times in opposite directions and longitudinally of said rodlike clement.

References Cited by the Examiner UNITED STATES PATENTS 731,883 6/1903 Fredenburgh 5777.35

FOREIGN PATENTS 1,317,476 1/1963 France.

650,950 3/1951 Great Britain. 615,223 1/1961 Italy.

0 FRANK I. COHEN, Primary Examiner.

I. PETRAKES, Assistant Examiner. 

1. A PULLING DEVICE FOR PERIODICALLY PULLING WOOLEN YARN PASSING THROUGH A DRAFTING ARRANGEMENT, COMPRISING: A STATIONARY YARN GUIDE PLACED IN THE DRAFTING ARRANGEMENT TRANSVERSELY TO THE DIRECTION OF MOVEMENT OF THE YARN AND ENGAGING WITH THE YARN, AND A ROTATING YARN GUIDE CONSTITUTED BY A RODLIKE ELEMENT PLACED IN THE DRAFTING ARRANGEMENT NORMAL TO THE DIRECTION OF MOVEMENT OF THE YARN AND ROTATABLE AROUND AN AXIS EXTENDING THROUGH THE CENTER OF SAID ELEMENT AND SUBSTANTIALLY COINCIDING WITH THE PATH OF THE YARN, SAID YARN GUIDES BEING PLACED AT A SMALL DISTANCE FROM ONE ANOTHER FOR AFFORDING PASSAGE OF THE YARN BETWEEN SAID GUIDES, SAID RODLIKE ELEMENT HAVING A SURFACE CURVED SEVERAL TIMES IN OPPOSITE DIRECTIONS AND LONGITUDINALLY OF SAID RODLIKE ELEMENT. 